package database

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5/pgxpool"
)

// DB represents a PostgreSQL database connection pool
type DB struct {
	Pool *pgxpool.Pool
}

// New creates a new database connection pool
func New(ctx context.Context, dbURL string) (*DB, error) {
	if dbURL == "" {
		return nil, fmt.Errorf("database URL is required")
	}

	config, err := pgxpool.ParseConfig(dbURL)
	if err != nil {
		return nil, fmt.Errorf("failed to parse database URL: %w", err)
	}

	// Limit pool size to prevent overloading the database.
	// pgxpool defaults to runtime.NumCPU which can be too high.
	if config.MaxConns == 0 {
		config.MaxConns = 10
	}
	if config.MinConns == 0 {
		config.MinConns = 2
	}

	pool, err := pgxpool.NewWithConfig(ctx, config)
	if err != nil {
		return nil, fmt.Errorf("failed to create connection pool: %w", err)
	}

	// Verify the connection
	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("failed to ping database: %w", err)
	}

	return &DB{Pool: pool}, nil
}

// Close closes the database connection pool
func (db *DB) Close() {
	if db.Pool != nil {
		db.Pool.Close()
	}
}